1, soda
Soda is a transliteration of SODA, and its chemical formula is Na2CO3. The scientific name of sodium carbonate is soda, also known as soda ash or baking soda powder. The one with crystal water is called hydrated sodium carbonate.
Anhydrous sodium carbonate is white powder or fine particles, easily soluble in water, and its aqueous solution is alkaline. It has strong hygroscopicity and can absorb moisture in the air to form lumps.
Among the three kinds of soft drinks, sodium carbonate is the most widely used. It is a very important chemical product and an important raw material for glass, soap, textile, paper making, leather making and other industries. It is also used in metallurgical industry and water purification. It can also be used to make other sodium compounds.
2. Sodium bicarbonate
The chemical formula of baking soda is NaHCO3. Scientific name of sodium bicarbonate, common name of baking soda.
Baking soda is a white crystal, easily soluble in water, and its aqueous solution is weakly alkaline. In hot air, it can slowly decompose and release a part of carbon dioxide; When heated to 270℃, carbon dioxide is completely decomposed and released.
2 sodium bicarbonate = = sodium carbonate +H2O+ carbon dioxide
Baking soda has many important uses in production and life. In fire extinguishers, it is one of the raw materials to produce carbon dioxide; In the food industry, it is the main raw material of baking powder; It is also a common raw material for making cold drinks; Medically, it is a medicine for treating hyperacidity.
Step 3: soda
Baking soda is the common name of sodium thiosulfate, also known as hypo (transliteration of hypo), with five crystal waters (Na2S2O3? 5H2O), so it is also called sodium thiosulfate pentahydrate.
Sodium bicarbonate is colorless and transparent crystal, easily soluble in water, and its aqueous solution is weakly alkaline. Weathering in dry air above 33℃, losing crystal water. It is stable in neutral and alkaline solutions and will decompose rapidly in acidic solutions.
Soda has a strong complexing ability and can form a complex with silver bromide. It can be used as a fixing agent.
Soda also has strong reducibility, which can reduce substances such as chlorine.
It can also be used as a dechlorination agent for bleached cotton fabrics. Similarly, iodine stains on fabrics can also be removed with it.
In addition, baking soda is also used for tanning, electroplating and extracting silver from ores.
In middle school, we mainly study soda and baking soda. Soda is generally not emphasized.
Tip: What kind of soda is in soda water?
Soda water is an aqueous solution of sodium bicarbonate (baking soda), which contains weak alkalinity. In medicine, it can be sterilized for external use, neutralize the acid-base balance in the human body and change the acidic constitution. Soda water sold in the market is mostly synthetic carbonated drinks, in which carbon dioxide is pressed into pure drinking water and sweeteners and spices are added.